RÉSUMÉ
Objective: To evaluate fracture resistance of teeth restored with inlay restorations of direct and indirect composite resin. Methods:Three dimensional finite element analysis (3D FEA) was used in present research. Two types of load were applied to investigate the change of tooth fracture resistance after restored with MOD inlay. Group 1,2,3,and 4 were restored with four kinds of materials:group 1,indirect composite resin inlay( Tescera, Bisco USA);group 2, direct composite inlay(Renew Bisco USA);group 3,ceramic; and group 4, Co-Cr alloy. Defect tooth or intact one was served as the control group. Results:Tooth fracture resistance in group 1,2,3 and 4 were improved, Fracture resistance in group 1 and 2 were similar to intact tooth group, while the fracture resistance in group 3 and 4 was different effect when compared to intact tooth. Conclusion: Both direct and indirect composite resin inlay could strengthen fracture resistance of restored teeth. No obvious difference between direct and indirect composite resin on tooth resistance was found.